Update documentation to reflect the new phandle support when OF_PLATDATA is used. Now phandles are implemented as pointers to U_BOOT_DEVICE, which makes it possible to get a pointer to the actual device.
Signed-off-by: Walter Lozano walter.lozano@collabora.com --- doc/driver-model/of-plat.rst | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/doc/driver-model/of-plat.rst b/doc/driver-model/of-plat.rst index aa0c8dde91..67477feec3 100644 --- a/doc/driver-model/of-plat.rst +++ b/doc/driver-model/of-plat.rst @@ -69,9 +69,8 @@ strictly necessary. Notable problems include: - Correct relations between nodes are not implemented. This means that parent/child relations (like bus device iteration) do not work yet. Some phandles (those that are recognised as such) are converted into - a pointer to platform data. This pointer can potentially be used to - access the referenced device (by searching for the pointer value). - This feature is not yet implemented, however. + a pointer to struct driver_info. This pointer can be used to access + the referenced device.
How it works @@ -146,10 +145,10 @@ and the following device declaration: .clock_freq_min_max = {0x61a80, 0x8f0d180}, .vmmc_supply = 0xb, .num_slots = 0x1, - .clocks = {{&dtv_clock_controller_at_ff760000, 456}, - {&dtv_clock_controller_at_ff760000, 68}, - {&dtv_clock_controller_at_ff760000, 114}, - {&dtv_clock_controller_at_ff760000, 118}}, + .clocks = {{NULL, 456}, + {NULL, 68}, + {NULL, 114}, + {NULL, 118}}, .cap_mmc_highspeed = true, .disable_wp = true, .bus_width = 0x4, @@ -164,6 +163,13 @@ and the following device declaration: .platdata_size = sizeof(dtv_dwmmc_at_ff0c0000), };
+ void populate_phandle_data(void) { + dtv_dwmmc_at_ff0c0000.clocks[0].node = DM_GET_DEVICE(clock_controller_at_ff760000); + dtv_dwmmc_at_ff0c0000.clocks[1].node = DM_GET_DEVICE(clock_controller_at_ff760000); + dtv_dwmmc_at_ff0c0000.clocks[2].node = DM_GET_DEVICE(clock_controller_at_ff760000); + dtv_dwmmc_at_ff0c0000.clocks[3].node = DM_GET_DEVICE(clock_controller_at_ff760000); + } + The device is then instantiated at run-time and the platform data can be accessed using:
@@ -329,7 +335,9 @@ prevents them being used inadvertently. All usage must be bracketed with #if CONFIG_IS_ENABLED(OF_PLATDATA).
The dt-platdata.c file contains the device declarations and is is built in -spl/dt-platdata.c. +spl/dt-platdata.c. It additionally contains the definition of +populate_phandle_data() which is responsible of filling the phandle +information by adding references to U_BOOT_DEVICE by using DM_GET_DEVICE
The beginnings of a libfdt Python module are provided. So far this only implements a subset of the features.